\\[-1.8ex] Soil Heterogeneity & $-$0.087$^{***}$ & $-$0.071$^{**}$ & $-$0.080$^{***}$ & $-$0.057$^{**}$ & $-$0.083$^{***}$ & $-$0.052$^{**}$ \\ 
  & (0.030) & (0.028) & (0.027) & (0.024) & (0.028) & (0.023) \\ 
\\[-1.8ex] 
Observations & 14,711 & 14,711 & 14,711 & 14,711 & 14,711 & 14,711 \\ 
R$^{2}$ & 0.395 & 0.450 & 0.407 & 0.481 & 0.401 & 0.493 \\ 
